REDUCING THE PEAK-TO-AVERAGE POWER RATIO OF OFDM SYSTEM WITH LOW COMPLEXITY

This paper proposes a companding scheme, where small signals are enlarged and large signals are reduced, to reduce the Peak-to-Average Power Ratio(PAPR). Computer simulation results show that the proposed technique has two advantages at least when compared with the conventional methods such as partial transmit sequence, selective mapping and the previous companding. First, it gets better PAPR performances with a lower complexity. Second, the scheme achieves greater performances gain with hardly any damnification of OFDM signals in some degree.

A Novel Peak-to-Average Power Ratio Reduction Scheme via Tone Reservation in OFDM Systems

In this paper, a novel signal-to-clipping noise ratio and least squares approximation tone reservation scheme(SCR-LSA TR) is proposed to reduce the peak-to-average power ratio for orthogonal frequency division multiplexing systems. During the SCR procedure, only the element with the maximal amplitude is picked for processing, which not only decreases the algorithm complexity, but also helps to overcome the BER deterioration. With the LSA method, the amplitude of the peak-cancelling signals can approximate to that of the original clipping noise as much as possible. Through the combination of the optimization factor in the LSA method, the classic SCR method can achieve better PAPR reduction with faster convergence. Simulation results show that the proposed SCR-LSA TR scheme has less in-band distortion and smaller out-of-band spectral radiation. The BER of the proposed scheme shows a better performance especially under the 16-QAM over the additive white Gaussian noise channel.

Simulation on Peak-to-Average Power Ratio for Orthogonal Frequency Division Multiplexing

Clipping is a simple and convenient PAPR （peak-to-average power ratio） reduction method for high speed OFDM （orthogonal frequency division multiplexing） communication system. In this paper, we propose a new PAPR reduction method for Wireless-MAN（metropolitan area network）-OFDM system based on IEEE 802.16, which is over-sampling clipping arithmetic. Simulation and performance of the over-samples clipping＇s PAPR reduction capability, BER effect is given. The simulation indicates that the PAPR of at least 99.9% OFDM symbol is below 6dB after 2 Nyquist rate clipping, and the performance of BER has 1dB SNR（signal noise ratio） loss. The results prove that this method has better capacity to reducing PAPR. So it can be well used in WMAN-OFDM system.

COMPLEMENT BLOCK CODING SCHEME FOR REDUCING PEAK-TO-AVERAGE POWER RATIO OF OFDM SYSTEMS

A new scheme termed as Complement Block Coding (CBC) technique is proposed to reduce the Peak-to-Average Power Ratio (PAPR) of OFDM signals. Utilizing the complement bits which are added to the original information bits,this method can effectively reduce the PAPR of OFDM systems with random frame size N and the coding rate R ≤ (N - k)/N, where kis a positive integer and k ≤ N/2. The performance results obtained with CBC are given and compared with that of some well known schemes, such as Simple Block Coding (SBC), Modified Simple Block Coding (MSBC) and Simple Odd Parity Code (SOPC) for the same purpose. The results show that, at the same coding rate 3/4, the CBC can achieve almost the same performance as SBC, MSBC, but with lower complexity, and that the same performance can be obtained with higher coding rate by using CBC. At the same coding rate (N - 1)/N, the PAPR reduction of CBC is almost the twice as that of SOPC when N ≥ 16. Further more, the PAPR reductions with coding rate (N - 1)/N are almost the same as that with coding rate less than (N - 1)/N,so the proposed scheme CBC is more suitable for the large frame size with high coding rate and can provide error detection.

Peak-to-average power ratio reduction using selective mapping with unequal power distribution

A new approach for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems was proposed.This approach is based on assigning powers to the different subcarriers of OFDM using an unequal power distribution strategy.In addition,a reduced complexity selective mapping (RC-SLM) scheme was proposed.The proposed scheme is based on partitioning the frequency domain symbol sequence into several sub-blocks,and then each sub-block is multiplied by different phase sequences whose length is shorter than that used in the conventional SLM scheme.Then,a kind of low complexity conversions is used to replace the IFFT blocks.The performance of the proposed RC-SLM scheme along with the new approach was studied with computer simulation.The obtained results show that the proposed RC-SLM scheme is able to achieve the lowest computational complexity when compared with other low complexity schemes proposed in the literature while at the same time improves the PAPR reduction performance by about 0.3 dB.

数据库设计工具的选择——Erwin,Power Designer,Rational Rose

随着数据库设计的需要,越来越多的CASE工具出现在我们的视野里,如何选择适合自己的工具就成了当务之急,下面对几种常用的工具Erwin,Power Designer,Rational Rose做以下对比。

Asymmetry Is Itself Symmetry： The Dilemma of Rationality-Power Relationship

Bent Flyvbjerg＇s research reveals a context dependent asymmetrical relationship between rationality and power, causing the so-called illegitimate rationalization to affect the decision-making process. This paper explores the nature of relationship between rationality and power by following Russell＇s philosophy and logic. The paper demonstrates how a symmetrical relationship may be transformed into an asymmetrical relation. Any study suggesting asymmetrical relationship between rationality and power may not be able to explain the relational dynamics of the two terms, By questioning the rationality-power asymmetrical relationship, the paper stresses the need to define the degree of asymmetry between rationality and power. The paper suggests a need for better interpretation and relational understanding of rationality-power relations for effective decision-making.

Cold wave caused power supply reducing and rationing

Because of the amalgamation of coal resourcesin Shanxi Province in 2009, coal production centermoved westward in China. The coal outputs of InnerMongolia and Shaanxi got higher. From January

具身主体的数字化:公、私道德失范的伦理研究

数字网络作为现代人生存的场域,具有雅努斯(Janus)头颅式的双面性,在促进主体的主体性解放的同时,也遮蔽了主体与对象、社会的距离,造成主体在道德上的结构性失语和功能性弱化,使主体的“具身存在”和“数字存在”同时受社会技术和自我技术的双重规范,诱发主体性畸变,其危害同时冲击数字网络和现实社会。因此,立足于具身主体的现代技术遮蔽,以康德、霍克海默、福柯对“启蒙”的界定为出路,有利于挖掘主体在数字网络“座架”中的道德失范现象,揭示现代社会启蒙事业的“未竟性”;同时在道德失范现象的基础上以现象学为视角、以“反思性判断”为方法来探索个体和社会作为双重主体伦理启蒙的可能性,不仅可以展现二者理性转向的内在互构关系,即完成主体间互为主体的内在自主启蒙和社会自身的双向变革,还可以实现道德由“施动型的知识灌输”向“自主型伦理启蒙”的转向,为揭橥“自由人与自由人的联合”的理论进路、形塑“非社会的社会”的存在样态开显可能的未来视域。

Rational统一过程在开发电网仿真系统中的应用

阐述了Rational统一过程的基本特征和工作流,且将RUP引入电网仿真系统的开发过程,建立了电网仿真系统基于RUP的用例模型和系统构架,给出了电网仿真系统的迭代实现过程,并对RUP进行了总结。

On the Coalitional Rationality and the Inverse Problem for Shapley Value and the Semivalues

In cooperative game theory, a central problem is to allocate fairly the win of the grand coalition to the players who agreed to cooperate and form the grand coalition. Such allocations are obtained by means of values, having some fairness properties, expressed in most cases by groups of axioms. In an earlier work, we solved what we called the Inverse Problem for Semivalues, in which the main result was offering an explicit formula providing the set of all games with an a priori given Semivalue, associated with a given weight vector. However, in this set there is an infinite set of games for which the Semivalues are not coalitional rational, perhaps not efficient, so that these are not fair practical solutions of the above fundamental problem. Among the Semivalues, coalitional rational solutions for the Shapley Value and the Banzhaf Value have been given in two more recent works. In the present paper, based upon a general potential basis, relative to Semivalues, for a given game and a given Semivalue, we solve the connected problem: in the Inverse Set, find out a game with the same Semivalue, which is also coalitional rational. Several examples will illustrate the corresponding numerical technique.

On the Coalitional Rationality of the Banzhaf Value and Other Non-Efficient Semivalues

In the Inverse Set relative to a Semivalue, we are looking for a new game for which the Semivalue of the original game is coalitional rational. The problem is solved by means of the Power Game of the given game. The procedures of building the new game, as well as the case of the Banzhaf Value are illustrated by means of some examples.

Science Letters:Peak-power reduction by the lattice-reduction-aided closest point search for MIMO broadcast channels

In this letter, we present a modified vector-perturbation precoding scheme for the multiple-input multiple-output broadcast channel, where a perturbation vector is chosen to take into account both the instantaneous power and the instantaneous peak power of the transmitted signal. This perturbation vector is obtained by using the closest point search, with the aid of the lattice-reduction algorithm. Simulation results show that the proposed scheme yields a tradeoff among power efficiency, peak-to-average power ratio reduction, and complexity.

Performance analysis of CDMA power control system based on fuzzy prediction

Power control is of paramount importance in combating the near-far problem and co-channel interference in a CDMA cellular system. Due to fast fading and ambient interference in a wireless channel, conventional fixed-step power control schemes have difficulty in compensating for the fast fading channel dynamically and in a timely manner. To acquire flexible power regulation in order to maintain required transmission capacity under the given transmission quality requirement, we propose a hybrid power control scheme which makes full use of the simple fuzzy inference rule refined by an operator in the fuzzy control and prediction property from related previous results in Generalized Prediction Control (GPC). In implementation of this strategy, we classify the fading zone into three levels according to the signal-to-noise-rate (SNR) requirement. In each level the power compensation amount varies with fading gradient and the compensation scheme varies as well. The digital results show that adoption of the fuzzy-GPC power regulation scheme has acquired a reasonable performance improvement when compared with fixed-step and fuzzy schemes. According to theoretic analysis and simulation results, we can conclude that under a variational transmission environment, a flexible power regulation scheme such as fuzzy-GPC is easy to adapt to the environment and thus overcomes the near-far effect and multi-access interference effectively.

Polynomial Functions Composed of Terms with Non-Integer Powers

Polynomial functions containing terms with non-integer powers are studied to disclose possible approaches for obtaining their roots as well as employing them for curve-fitting purposes. Several special cases representing equations from different categories are investigated for their roots. Curve-fitting applications to physically meaningful data by the use of fractional functions are worked out in detail. Relevance of this rarely worked subject to solutions of fractional differential equations is pointed out and existing potential in related future work is emphasized.

在“行政效率”与“地方文化网络”之间:乡镇基层治理的综合情理与实践智慧

“情理”在中国基层社会治理中有着举足轻重的结构位置,但其具体实践依然有进一步研究的空间。浙北W镇综合行政执法分局的基层实践,根据基层行政执法部门的行动指向和实际控制权两个维度,采取了秉持人文关怀、外借权威、联合避责等行动策略,以应对治理场景下的工作压力和提高治理效果。执法部门的“情理”运作有着深刻的实践逻辑,即在提升政府治理效能、符合社会期待、维持部门组织自主性、降低治理风险性等多维的情理维度之间寻求平衡,这是“行政效率”与“地方文化网络”动态交互而成的实践智慧。

中国式现代化理论的标识性范畴与体系化构建

中国式现代化范畴既有从探索提出到形成确立的逻辑演进过程,也有从简单范畴到范畴体系的逻辑展开过程。中国式现代化是新时代党的理论创新的标识性范畴,但作为一个科学理论体系,中国式现代化理论自身也包含着一系列标识性范畴,这些范畴揭示了中国式现代化的内涵、特征和本质,使中国式现代化更加清晰、科学、可感可行。中国式现代化理论的标识性范畴为构建中国式现代化理论的科学体系,提炼中国式现代化理论的基本原理,提升中国式现代化理论的话语说服力和影响力,进而推进中国式现代化理论的体系化、学理化,奠定了坚实的概念基石和理论基础。提炼并阐明中国式现代化理论的标识性范畴,是构建具有学理性的中国式现代化理论体系的基础工作和必要环节。

经济法的立法路径审视及其改革

立法是法治的基础,这对以立法主体主动建构规则为重要特征的经济法尤为重要。经过多年改革,当前我国的经济立法在立法动因上体现出政策驱动性和实践回应性,在立法体系上体现出横向协同性和纵向续造性,在立法模式上体现出授权性和试验性,促进了经济立法的发展和进步。但同时,也存在对多元立法目标平衡不足、立法权配置的整合与统筹不力、对立法合理性和立法效果评估不够重视等问题。对此,应以规则合理性为标准,进一步深化经济法立法路径的改革,重点加强立法主体的说明解释机制,促进经济立法权的合理分配与整合,致力于立法合理性最大化,并构建和完善立法后评估制度。

资源保存理论视域下我国职业足球发展的理性审视

中国职业足球发展30年,出现了诸多社会性问题,给中国体育和中国足球带来破坏性影响。为积极探索新发展阶段我国职业足球面临的新问题与新挑战,运用文献研究、逻辑分析、案例研究等方法对我国职业足球发展问题进行分析。研究发现:现阶段,我国职业足球发展存在职业足球管理主体权限不清、责任不明,职业足球发展监管缺位,职业足球从业者道德迷失,职业俱乐部价值目标迷离等失范问题。在资源保存理论视域下审视这些问题,结合加快建设体育强国的背景,提出全面振兴策略:厘清我国职业足球现有资源存量,推动不同资源间的交互作用;结合我国职业足球资源动态过程,形成资源波动上的螺旋机制;合理促进职业足球资源人际流动,实现振兴发展上的群体效能。

数字时代下的算法理性与算法权力——对算法权力中人的处境的再思考

在霍克海默与阿多诺的笔下,作为一种“工具一般”的理性成为符合资本主义异化逻辑中对主体的压制性力量。伴随着人工智能、元宇宙等数字技术的飞速发展,需要对数字时代下的“工具一般”进行重新思考。从历史唯物主义的角度出发,在马克思所处的产业资本主义时期,工人被当作机器的有机形式围绕着机器的逻辑运转;而在鲍德里亚的“物体系”当中,人们进行消费的不再是商品的功能性,而是一种符号价值。也就是说,所有人都被商品物的符号—象征法则所支配;算法成为数字资本主义的权力载体,在算法理性的支配下,所有人都以一种数字的“非人”状态被裹挟进数字资本的生产之中。从无意识的工具、无主体的统治以及再划分的边界这三个层面重新理解人与算法权力的关系具有较强的现实意义。